Device and method for determining the presence of middle ear fluid

ABSTRACT

A device for determining the presence of abnormal fluid in a middle ear of a subject includes an elongated probe, a first light source housed within the elongated probe, and a second light source housed within the elongated probe. The elongated probe includes a distal end for inspection of an ear. The First light source is configured to convey an optical beam through a tympanic membrane associated with the middle ear of the subject, without puncturing the tympanic membrane. The second light source is configured to convey light through the distal end of the elongated probe and illuminate the tympanic membrane.

RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/410,114, filed Nov. 4, 2010, the entirety ofwhich is hereby incorporated by reference for all purposes.

TECHNICAL FIELD

The present invention relates generally to the field of otolaryngology,and more specifically to a device and method for determining thepresence of fluid in the middle ear of a subject.

BACKGROUND OF THE INVENTION

Otitis media (ear infection) is a common problem that bears significanthealth implications. It is the most common cause of deafness in childrenin the developed world, affecting up to 80% of preschool children atsome time. Second only to upper respiratory infections, it is the mostcommon indication for outpatient antibiotic use in children. Further, itis the most common reason for a child to visit the pediatrician. In theUnited States, the annual cost of medical and surgical treatment ofotitis media is estimated at $5 billion.

Otitis media is an inflammatory and infective process affecting themiddle ear and mastoid spaces. After an acute infection, there is oftenthe development of persistent fluid within the middle ear space, knownas a middle ear effusion (MEE). Persistence of a MEE can result inhearing loss and recurrent otitis media with effusion (OME). OME isdefined as the presence of a middle ear effusion for 3 months or morewithout gross signs of middle ear infection. However, recurrent earinfections often ensue in OME as the presence of effusion creates afertile environment for bacterial growth.

The middle ear normally produces mucus. However, inflammatory stimuli,such as bacteria, virus, and allergy, may cause excessive production,increased viscosity, or impaired drainage of the mucus. These changeslead to mucus collection within the middle ear, forming a MEE. MEEs maypersist for prolonged durations, especially in children, resulting inhearing loss and recurrent ear infections. Adults may also develop OMEand persistent MEE, but are less susceptible than children in most partdue to improved Eustachian tube function and position. In both adult andpediatric populations, treatment options typically include ear tubeplacement or close observation for resolution.

With these important clinical implications, accurate interpretation ofmiddle ear contents proves to be an important and essentialdetermination during the ear examination in all patients. The presenceof middle ear fluid is commonly assessed by the existing technologies ofotoscopy and tympanometry. However, these both have limitations indiagnostic accuracy and are dependent on the practitioner's experience,warranting consideration of alternate technologies. Tympanometry, forexample, is a measure of the compliance of the tympanic membraneobtained by altering the air pressure within the ear canal and is not atrue measure of the middle ear space. Therefore, the tympanometry probeplaced in the external ear canal must achieve a tight seal, which isdifficult to obtain in young children.

SUMMARY OF THE INVENTION

In one aspect of the present invention, a device is provided fordetermining the presence of abnormal fluid in a middle ear of a subject.The device includes an elongated probe, a first light source housedwithin the elongated probe, and a second light source housed within theelongated probe. The elongated probe includes a distal end forinspection of an ear. The first light source is configured to convey anoptical beam through a tympanic membrane associated with the middle earof the subject, without puncturing the tympanic membrane. The secondlight source is configured to convey light through the distal end of theelongated probe and illuminate the tympanic membrane.

Another aspect of the present invention includes a method fordetermining the presence of abnormal fluid in a middle ear of a subject.One step of the method comprises providing a device. The devicecomprises an elongated probe having a distal end, a first light sourcehoused within the elongated probe, and a second light source housedwithin the elongated probe. The first light source is activated toconvey an optical beam through the tympanic membrane, without puncturingthe tympanic membrane. The conveyed optical beam creates a reflectancepattern associated with the tympanic membrane. Next, the reflectancepattern is observed. A substantially diffuse reflectance patternindicates the presence of abnormal fluid in the middle ear of thesubject.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the present invention will becomeapparent to those skilled in the art to which the present inventionrelates upon reading the following description with reference to theaccompanying drawings, in which:

FIG. 1 is a schematic illustration showing a device for determining thepresence of fluid in a middle ear of a subject constructed in accordancewith one aspect of the present invention;

FIG. 2 is a schematic illustration showing a cross-sectional view of ahuman ear;

FIG. 3A is a schematic illustration showing a magnified view of firstand second light sources housed within the device in FIG. 1;

FIG. 3B is a schematic illustration showing an alternative configurationof the first light source in FIG. 3A;

FIG. 4 is a process flow diagram illustrating a method for determiningthe presence of an abnormal fluid in the middle ear of a subjectaccording to another aspect of the present invention;

FIG. 5A is a schematic illustration showing the device of FIG. 1inserted into the ear of a subject;

FIG. 5B is a schematic illustration showing activation of the first andsecond light sources in FIG. 1;

FIG. 6A is a schematic illustration showing a reflectance patternassociated with a tympanic membrane that indicates the absence of fluidin the middle ear of a subject;

FIG. 6B is a schematic illustration showing a reflectance patternassociated with a tympanic membrane that indicates the presence ofabnormal fluid in the middle ear of a subject;

FIG. 7A is a schematic illustration showing diffuse light passingthrough the tympanic membrane in FIG. 6A;

FIG. 7B is a schematic illustration showing diffuse light passingthrough the tympanic membrane in FIG. 6B; and

FIG. 8 is a series of photographic images showing reflectance patternsassociated with a tympanic membrane without effusion, with cleareffusion, and with yellow effusion using a green laser (532 nm), a redlaser (635 nm), and a UV/blue laser (405 rim).

DETAILED DESCRIPTION

Unless otherwise defined, all technical terms used herein have the samemeaning as commonly understood by one of ordinary skill in the art towhich the present invention pertains.

In the context of the present invention, the term “light” can refer toelectromagnetic radiation over the entire spectrum of wavelengths, suchas ultraviolet, visible and infrared.

As used herein, the term “subject” can refer to any animal including,but not limited to, humans and non-human animals (e.g., non-humanprimates, ovines, bovines, etc.). Typically, the terms “patient” and“subject” are used interchangeably herein in reference to a humansubject.

The present invention relates generally to the field of otolaryngology,and more specifically to a device and method for determining thepresence of fluid in the middle ear of a subject. The present inventionprovides a device 10 (FIG. 1) and method 12 (FIG. 4) for increasing thediagnostic abilities of conventional otoscopic devices found in mostclinicians' offices, emergency departments, and clinics. The presentinvention is based, at least in part, on the discovery that an opticalbeam, such as a coherent optical beam (e.g., a low power laser) may beilluminated onto the tympanic membrane, and that the resultantreflectance pattern associated with the tympanic membrane and middle earspace is telling of whether there is abnormal fluid in the middle ear ofa subject. Based on this discovery, the present invention significantlyincreases the diagnostic accuracy of otoscopy, which is an essentialpart of the physical examination performed by different practitioners ina vast number of settings (e.g., pediatricians, emergency physicians,otolaryngologists, nurse practitioners, etc.).

Existing technologies for assessing the presence of fluid in the middleear are limited in their ease-of-use and accuracy. The present inventionis based on the premise that a medical practitioner can perform otoscopyin nearly every patient with relative ease. The present invention is asimple, cost-effective, and easily interpretable addition toconventional otoscopy that provides critical information about thepresence of fluid in the middle ear. As described in more detail below,the present invention eliminates the need for additional devices,testing, personnel, and computerized interpretation, thereby leading todecreased costs.

To assist the reader in understanding the relative anatomy andphysiology to which the present invention pertains, a schematicillustration showing a cross-sectional view of a human ear 14 is shownin FIG. 2. There are three components to the ear 14: the outer ear; themiddle ear; and the inner ear. All three are involved in hearing, butonly the inner ear is responsible for balance. The outer ear is composedof the pinna, or ear lobe, and the external auditory canal. Bothstructures funnel sound waves towards the ear drum or tympanic membraneallowing it to vibrate. The pinna is also responsible for protecting theear drum from damage.

The middle ear is an air-filled space located in the temporal bone ofthe skull. Air pressure is equalized in this space via the Eustachiantube, which drains into the nasopharynx and nose. There are three smallbones, or ossicles, located adjacent the tympanic membrane. The malleus,incus, and stapes are attached like a chain to the tympanic membrane andconvert sound waves that vibrate the membrane into mechanical vibrationsof these three bones. The stapes fills the oval window, which is theconnection to the inner ear.

The inner ear has two functions—hearing and balance. The inner ear is awarren of tubes filled with fluid and encased within the temporal boneof the skull. The bony tubes also contain a set of cell membrane-linedtubes. The bony tubes are called the bony labyrinth, which are filledwith perilymph fluid, while the membranous labyrinth tubes are filedwith endolymph. This is where the cells responsible for hearing arelocated (i.e., the hairy cells of Corti). The bony labyrinth itself hasthree sections: (1) the cochlea is responsible for hearing; (2) thesemicircular canals have function associated with balance; and (3) thevestibule, which connects the two structures and contains two morebalance and equilibrium related structures, the saccule and utricle. Thefinal structures of the inner ear are the round window and the eighthcranial nerve (cranial nerve VIII), which is composed of the vestibularnerve and the cochlear nerve.

One aspect of the present invention includes a device (FIG. 1) fordetermining the presence of fluid (e.g., abnormal fluid) in the middleear of a subject. The device 10 comprises an elongated probe 16 and afirst light source 18 that is housed within the elongated probe. Theelongated probe 16 is generally T-shaped and includes a distal end 20for inspection of an ear 14, such as the auditory canal. The elongatedprobe 16 further includes a grip section 22 that supports a probesection 24 and an eyepiece 26, each of which extends in oppositedirections. The distal end 20 of the elongated probe 16 also includes atip 28, which can be positioned a desired distance (e.g., about 5-10 mm)from the tympanic membrane during use of the device 10.

In another aspect of the present invention, the device 10 comprises amodified otoscope as shown in FIG. 1. Otoscopes generally consist of ahandle and a head. The head can contain a light source and a simplelow-power magnifying lens, typically around 8 diopters. The distal orfront end of the otoscope has an attachment for disposable plastic earspecula. In one example of the present invention, the device 10comprises a modified open otoscope. Open otoscopes are similar toconventional (closed) otoscopes, except that there is no encasingbetween the lens and the ear speculum. The open otoscope is often usedin otolaryngology to insert instrumentation within the ear 14 (e.g., toremove ear wax under otoscopic visualization). Open otoscopes arecommercially available from Welch Allyn. (Skaneateles, N.Y.), forexample. It will be appreciated that the otoscope can optionallycomprise a conventional or closed otoscope (i.e., with encasing betweenthe lens and the ear speculum).

As shown in FIG. 3A, the device 10 is modified to include a first lightsource 18 configured to convey an optical beam 30 (FIG. 5B) through atympanic membrane associated with a middle ear of a subject. The device10 (FIG. 3A) can additionally or optionally include a second lightsource 32 that is housed therein and configured to convey light throughthe distal end 20 of the elongated probe 16, thereby illuminating thetympanic membrane of the subject. In one example of the presentinvention, the second light source 32 can comprise an incandescentlight. The second light source 32 can be operably connected to a dimmerswitch (not shown), which allows the intensity of the second lightsource to be modulated (e.g., decreased) during use of the device 10.

The first light source 18 and/or the second light source 32 can be inelectrical communication with the same or different power source(s) (notshown). For example, the first light source 18 and the second lightsource 32 can be in electrical communication with a single batteryhoused within the device 10. As described in more detail below, thisconfiguration is possible because the first light source 18 onlyrequires low power to operate. It will be appreciated that other sourcesof power, such as external batteries and/or power outlets, may also beused to provide energy to the first and second light sources 18 and 32.

The first light source 18 can be a lower power source of the opticalbeam 30 (e.g., an ANSI Class IIIR device) (FIG. 5B). For example, thefirst light source 18 (FIG. 3A) can operate at a power of less thanabout 10 mW. In another example, the first light source 18 can operateat a power of less than about 5 mW. In a further example, the firstlight source 18 can operate at a power of greater than about 1 mW butless than about 5 mW. Advantageously, low power operation of the firstlight source 18 allows the optical beam 30 (FIG. 5B) to be conveyedthrough the tympanic membrane without puncturing or disrupting thetympanic membrane. This is unlike otoscopes used during myringotomyprocedures, in which a high power coherent optical beam (e.g., a laser)is used to pierce the tympanic membrane and create a tiny incisiontherein.

The first light source 18 (FIG. 3A) is configured to deliver an opticalbeam 30 (FIG. 513) of light. For example, the first light source 18(FIG. 3A) can be a laser that is configured to deliver a collimated orfocused optical beam 30 (FIG. 5B) having one or more wavelengths in thevisible spectrum. In one example of the present invention, the firstlight source 18 (FIG. 3A) is configured to deliver a coherent opticalbeam 30 (FIG. 5B) having a wavelength of about 532 nm. In anotherexample of the present invention, the first light source 18 (FIG. 3A) isconfigured to deliver a coherent optical beam 30 (FIG. 53) having awavelength of about 635 nm. A variety of known electromechanical devicesmay be used as the first light source 18 (FIG. 3A), such as lightemitting diodes (LEDs), lasers and laser diodes. For example, the firstlight source 18 can comprise a low power laser diode configured toconvey a coherent optical beam 30 (FIG. 5B) having a wavelength of about532 nm or about 635 nm.

It will be appreciated that first light source 18 (e.g., a laser diode)(FIG. 3A) can be housed within the grip section 22 of the device 10. Inthis case, the optical beam 30 (FIG. 5B) can be propagated through oneor more optical fibers 34 (e.g., optic cable(s) or light pipe(s)) (FIG.3B) that extend from the first light source 18 through the device 10 tothe distal end 20 and/or the tip 28. Although not shown, it will also beappreciated that the device 10 of the present invention can includeadditional components and features to optimize certain functionsthereof. For example, the device 10 can include crossed polarizers toreduce the visibility of reflected light, an occluding mechanismconfigured to remove reflected light from the field of view, and/orcolor filters to improve visibility and contrast.

Another aspect of the present invention includes a method 12 (FIG. 4)for determining the presence of fluid (e.g., abnormal fluid) in themiddle ear of a subject. In one example of the present invention, themethod 12 can be used to determine the presence of MEE in a subject.After an acute ear infection, there is often the development ofpersistent fluid within the middle ear space, which is known as MEE.Persistence of MEE poses significant health problems of conductivehearing loss leading to speech and learning delays and recurrent OME.Therefore, correct diagnosis is paramount. The most commonly useddiagnostic methods include otoscopy and tympanometry; however, thesemethods have shown only limited accuracy and are dependent onpractitioner experience, leading to frequently incorrect diagnoses,unnecessary use of antibiotics, and prolonged hearing loss. As describedbelow, the present invention provides a simple and effective way formedical practitioners to detect abnormal fluid in the middle ear, suchas MEE and thereby correctly diagnose and treat the patient.

Step 36 of the method includes providing a device 10 that is identicallyor similarly constructed as the device shown in FIG. 1 and describedabove. For example, the device 10 can comprise a modified open otoscopehaving a distal end 20, a grip section 22, a first light source 18configured to convey an optical beam 30, and a second light source 32configured to convey light through the distal end.

The first light source 18 can comprise a low power (e.g., less thanabout 5 mW) diode (e.g., laser diode) configured to convey a coherentoptical beam 30 having a wavelength of about 532 nm or about 635 nm.

The device 10 can then be positioned as shown in. FIG. 5A. For example,the distal end 20 of the device 10 can be inserted into the auditorycanal and then progressively advanced until the tip 28 is positionedadjacent the tympanic membrane. The tip 28 can be positioned adjacentthe tympanic membrane at a desired distance, as determined by themedical practitioner. For example, the tip 28 can be positioned about5-10 mm from the tympanic membrane. During positioning of the distal end20, the second light source 32 (e.g., an incandescent light source) canbe optionally activated to illuminate the auditory canal and thetympanic membrane.

After the distal end 20 of the device 10 is appropriately positioned inthe auditory canal of the subject, the first light source 18 isactivated at Step 38 (FIG. 5B). If it has not been done so already, thesecond light source 32 can also be activated at Step 38. The first lightsource 18 can be activated by a controller (not shown) (e.g., a button)located on the device 10. Activation of the controller can cause thefirst light source 18 to convey an optical beam 30 through the tympanicmembrane, but without puncturing or piercing the tympanic membrane. Whenthe optical beam 30 passes through the tympanic membrane, it isreflected back onto the tympanic membrane to create reflectance pattern44 associated with the tympanic membrane, which can be a substantiallyconcentrated reflectance pattern (FIG. 6A) or a substantially diffusereflectance pattern (FIG. 6B).

A reflectance pattern associated with a tympanic membrane can refer tolight reflected from the tympanic membrane, as well as diffusereflectance of light that is effused through the tympanic membrane(e.g., reflected from anything in the middle ear space). it will beappreciated that internal reflections in the tympanic membrane cancontribute to the reflectance pattern, as well as tympanic membranesurface reflections. As shown in FIGS. 6A-B, the reflectance pattern 44comprises at least two regions. A first region 46 of the reflectancepattern 44 is defined by a portion of the incident light or spot beam ofthe optical beam 30 reflected from the exterior surface of the tympanicmembrane. A second region 48 corresponds to the remaining portion of theincident light or spot beam of the optical beam 30 that is reflectedfrom the rear wall and/or fluid in the middle ear back toward thetympanic membrane and effuses through the tympanic membrane. A thirdregion 50 includes a portion of the tympanic membrane that is neithertransmissive nor reflective of any portion of the optical beam 30.

Alternatively, the reflectance pattern 44 can refer to the observedpattern comprising the sum of all light reflecting from the outer andinner surfaces of the tympanic membrane (and associated tissue), as wellas the middle ear space (and all tissue and fluid present within themiddle ear space). All the light that returns through the tympanicmembrane is then observed by the user of the device 10.

To appreciate the nature of the reflectance pattern 44 created by theoptical beam 30, it is important to appreciate the physical propertiesof light and the materials it traverses. Fundamentally, the middle earof a human resembles a drum. A thin, partially translucent tympanicmembrane is stretched over a cavity with mostly air space and a rearsurface. Under abnormal conditions, the air space becomes filled with aneffusion. Effusion fluid is characteristically variable in viscosity andtransparency. Despite this, the light scattering properties of the fluidare substantially different from air. Air is usually regarded as anon-scattering medium. The fluid present in the middle ear is stronglyforward scattering, but also includes significant scattering through areasonably wide angle. This effect is similar to a headlight shiningthrough fog.

In a healthy ear, the light path consists of two tissues and a total ofthree boundaries. Light shined into the auditory canal strikes theexternal surface of the tympanic membrane and then passes through thisthin membrane into the middle ear space. As the light passes through theair space of the middle ear essentially unchanged, it is reflected fromthe irregular surface of the middle ear and returns with a slightlybroader reflectance pattern 44 or reflected beam profile, which producesa substantially concentrated reflectance pattern (e.g., resembling adot) on the surface of the tympanic membrane (FIG. 7A). As used herein,the term “concentrated reflectance pattern” can refer to effusion oflight through the tympanic membrane that is substantially focused and/ornarrow based on the lower index of refraction of the air in the middleear. That is, the air within a normal middle ear has a low index ofrefraction, such that it has very little effect on the optical beam 30passing through the tympanic membrane (though, a certain amount may bereflected from the rear surface of the middle ear in the presence ofair).

In an abnormal or fluid-filled middle ear, the tympanic membrane andsurrounding tissues remain largely unchanged. However, the presence offluid drastically alters the optical effect of the middle ear. The fluid(and any scattering materials present within it, such as particulatematter and bacteria) will cause the optical beam to broadensignificantly more than the air in a middle ear without fluid, therebycreating a substantially diffuse reflectance pattern on the tympanicmembrane (FIG. 6B). As used herein, the term “diffuse reflectancepattern” can refer to effusion of light through the tympanic membranethat is substantially widely scattered and/or spread based on the verydifferent optical properties of the fluid in the middle ear relative toair (e.g., while the index of refraction is different, the scatteringfunctions of the fluid and associated particulates are also different).Therefore, a substantially diffuse reflectance pattern is such thatreflected light is substantially different than the substantiallyconcentrated reflectance pattern in terms of the observed reflectancepattern (e.g., more observed light in the substantially diffuse pattern)(FIG. 7B).

Additionally, the distance from the tympanic membrane to the tissues ofthe middle ear can be sufficient such that the light scattering can beperpendicular or even substantially retrograde to the original path ofthe optical beam 30. When light returns to the tympanic membrane, thebeam is significantly broader and may result in substantially completeillumination of the tympanic membrane.

As discussed earlier, the light that creates a substantially diffusereflectance pattern (in the presence of abnormal fluid) has a higherrefractive index as compared to the light that creates a substantiallyconcentrated reflectance pattern (in a normal middle ear). From anobserver standpoint (Step 40), it will appear that the entire tympanicmembrane has become illuminated with a “glow” when abnormal fluid ispresent. This is in stark contrast to the case of air in the middle ear,where the optical beam 30 will appear largely unchanged and appear as asubstantially concentrated reflectance pattern (e.g., similar to a dot)on the tympanic membrane.

At Step 42, a determination of whether there is abnormal fluid in themiddle ear is made. A substantially diffuse reflectance pattern (FIG.6B) indicates the presence of abnormal fluid in the middle ear. Forexample, the presence of a substantially diffuse reflectance pattern canindicate the presence of MEE in the subject. Alternatively, asubstantially concentrated reflectance pattern (FIG. 6A) indicates thepresence of normal fluid (i.e., air) in the middle ear. The presentinvention thus provides a simple and effective method 12 for diagnosingotitis media. The method 12 offers significant cost savings bydecreasing the number of false-negative diagnoses, which can lead tounnecessary use of antibiotics, increased bacterial resistance toantibiotics, and drive increase economic costs by heightening the costsassociated with treating more advanced disease.

The present invention is further illustrated by the following example,which is not intended to limit the scope of potential applications ofthe invention.

EXAMPLE Device Design

Initial device design centered on the addition of a laser diode moduleand mount to an existing open otoscope (Welch Allyn, Skaneateles Falls,N.Y.). For the purpose of the present invention, an open otoscope easilyallows positioning and adjustment of a tightly focused beam. A simplemount was built and attached to the otoscope near the light source tosecure the laser diode module.

This design allowed convenient replacement of the laser diode module sothat different wavelengths (colors) may be tested on the same prototype.Also, the mount allowed accurate and stable positioning of the laserdiode module so that the beam could be aimed through the opening of thespeculum and illuminate onto the tympanic membrane surface. For purposesof this prototype, the laser diode module was attached to the mount bydouble-sided tape, and power was achieved via an external batterysource. Power for the otoscope incandescent bulb was from a separatepower supply built into the original device.

Device Testing

An ex vivo cadaver specimen was obtained with permission that includedthe ear, middle ear, temporal bone, middle fossa floor, Eustachian tube,and surrounding structures (Cleveland Clinic Anatomy Lab). Experimentswere performed in the Cleveland Clinic Head and Neck Institute ResidentTraining Temporal Bone Lab (Crile Building). The specimen was anchoredin a temporal bone dissection apparatus, and the middle ear space wasaccessed via a middle cranial fossa approach. This access was necessaryto insert and remove synthetic effusion substitute.

Effusions of the middle ear are predominantly composed of mucin, a largeglycoprotein. A synthetic substitute for MEE or mucin is not available.Therefore, we created a synthetic substitute for effusion for thepurpose of proof-of concept testing. Surgilube (Fougera, Melville, N.Y.)was mixed with water to create a fluid with the color, consistency, andviscosity properties similar to native MEE. As MEE color can range fromclear to pale yellow, food coloring was added to also create a paleyellow effusion substitute. This effusion was placed within the middleear and then removed via the middle fossa approach superior to themiddle ear space without damaging or perforating the tympanic membrane.

With this experimental setup, we examined the effect of laser diodes ofthree different wavelengths on the tympanic membrane. Green (532 nm),red (635 nm), and blue/ultraviolet (405 nm) laser colors were chosen dueto their ready availability, size, visual spectrum coverage, andreasonable cost. Other colors (yellow, blue, etc.) either were of highcost (>$100) or had large modules that would not be practical for thisapplication. Three different experimental situations of the middle earwere assessed: no fluid present; clear fluid present; and yellow-greenfluid present. Visual documentation was performed with a camera, andresults are shown in FIG. 8.

Photography images were obtained via the lens of the device. While thelaser was engaged, the background lighting provided by the otoscope wasdimmed to provide improved assessment of the laser pattern. As describedpreviously, the laser was propagated from the device module platformthrough the speculum and onto the tympanic membrane. As shown in FIG. 8,the results present several important findings, including:

-   -   (1) without any laser assistance, otoscopy alone proves to be        insufficient to differentiate between no effusion, clear        effusion, and yellow effusion states;    -   (2) green (532 nm) laser-assisted visualization produces the        visual effects as hypothesized. The presence of effusion is        demonstrated with glow of the tympanic membrane, while when no        effusion is present the laser appears as a point. This effect        was demonstrated for both effusion types;    -   (3) red (605 nm) laser produced similar results as the green        laser;    -   (4) blue (405 nm) laser provided expected results for the clear        effusion state, but did not provide a glow for the yellow        effusion (possibly because digital (and film) cameras have        significantly more sensitivity in the UV region than the human        eye); and    -   (5) while the camera provides visual documentation of the        results, the extended sensitivity of the human eye over the        digital camera actually provides a clearer result than the        images shown in FIG. 8.

From the above description of the invention, those skilled in the artwill perceive improvements, changes and modifications. Suchimprovements, changes, and modifications are within the skill of the artand are intended to be covered by the appended claims.

Having described the invention, the following is claimed:
 1. A devicefor determining the presence of abnormal fluid in a middle ear of asubject, said device comprising: an elongated probe having a distal endfor inspection of an ear; a first light source configured to convey anoptical beam through a tympanic membrane associated with the middle earof the subject, without puncturing the tympanic membrane, said firstlight source being housed within said elongated probe; and a secondlight source configured to convey light through said distal end of saidelongated probe and illuminate the tympanic membrane, said second lightsource being housed within said elongated probe.
 2. The device of claim1, wherein said elongated probe comprises an otoscope.
 3. The device ofclaim 1, wherein said second light source comprises an incandescentlight source.
 4. The device of claim 1, wherein said first light sourceoperates at a power of less than about 10 mW.
 5. The device of claim 4,wherein said first light source operates at a power of less than about 5mW.
 6. The device of claim 1, wherein said first light source isselected from the group consisting of a light emitting diode (LED), alow power laser, and a low power laser diode.
 7. The device of claim 1,wherein said first light source is a lower power laser diode configuredto deliver a coherent optical beam having a wavelength of about 532 nm.8. The device of claim 1, wherein said first light source is a lowerpower laser diode configured to deliver a coherent optical beam having awavelength of about 635 nm.
 9. A method for determining the presence ofabnormal fluid in a middle ear of a subject, said method comprising thesteps of: providing a device comprising an elongated probe having adistal end, a first light source housed within the elongated probe, anda second light source housed within the elongated probe; activating thefirst light source to convey an optical beam through the tympanicmembrane without puncturing the tympanic membrane, the conveyed opticalbeam creating a reflectance pattern associated with the tympanicmembrane; and observing the reflectance pattern; wherein a substantiallydiffuse reflectance pattern indicates the presence of abnormal fluid inthe middle ear of the subject.
 10. The method of claim 9, wherein asubstantially concentrated reflectance pattern indicates the absence ofabnormal fluid in the middle ear of the subject.
 11. The method of claim9, wherein said step of providing a device further includes providing asecond light source comprising an incandescent light source and a firstlight source comprising a low power light source selected from the groupconsisting of a LED, a laser, and a laser diode.
 12. The method of claim11, further comprising the step of providing a low power laser diodeconfigured to operate at a power of less than about 10mW.
 13. The methodof claim 12, further comprising the step of providing a low power laserdiode configured to operate at a power of less than about 5 mW.
 14. Themethod of claim 9, wherein said step of activating the first and secondlight sources further includes activating the first light source toconvey a coherent optical beam having a wavelength of about 532 nm. 15.The method of claim 9, wherein said step of activating the first andsecond light sources further includes activating the first light sourceto convey a coherent optical beam having a wavelength of about 635 nm.16. The method of claim 9, wherein a substantially diffuse reflectancepattern indicates the presence of a middle ear effusion.